It has long been known to produce beverages of various formulations. Improved and new formulations are desirable to achieve desired nutritional characteristics, flavor, shelf life, and other objectives. For example, it would be desirable to provide a rehydration beverage that comprises protein.
Rehydration beverages may be used in conjunction with physical activity, such as exercise, to replenish fluids and electrolytes lost during the activity as well as to provide additional energy. To this end, rehydration beverages typically comprise at least water, carbohydrates and electrolytes.
In addition to electrolytes and carbohydrates, it may be desirable to consume protein following physical activity. Many protein beverages, however, are provided in the form of a shake or other product having a high viscosity. Consumption of such thick beverages may result in an undesirable feeling of fullness by the subject, leading the subject to consume an insufficient amount of the beverage to achieve complete rehydration or recovery. Moreover, intact proteins are typically sensitive to both heat and acidity, thus it would be desirable to employ a protein that can withstand processing and storage conditions in a recovery beverage composition.
It is an object of the invention to provide rehydration/recovery beverage compositions containing electrolytes and protein, which are easy to drink in sufficient quantities to achieve rehydration/recovery (e.g., are gulpable). Water, carbohydrates, and electrolytes are essential for re-hydration and re-energizing post workout. In particular, protein is important for post exercise muscle recovery. There are research articles regarding how protein intake following exercise can support muscle protein synthesis and inhibit protein breakdown under certain circumstances. In addition, certain amino acids may regulate key signaling pathways for protein translation. (See Wolfe, R. R., J. Nutr., 2006; 136:525 S-528S; Wolfe, R. R., J. Nutr., 2002; 132:3219 S-3224S; Kimball & Jefferson, Am. J. Clin. Nutr., 2006; 83:500 S-5007S, and Hartman et al., Am. J. Clin. Nutr., 2007; 86:373-381.) Research has also shown that the essential amino acid component of protein is capable of driving muscle protein synthesis to result in a net positive muscle protein balance following resistance exercise. (See Tipton et al., Am. J. Physiol., 1999; 276:E628-E634 and Volpi et al., Am. J. Clin. Nutr., 2003; 78:250-258.)
As little as six grams of essential amino acids may stimulate the positive protein balance after exercise, when ingested within three hours of the exercise. (See Rasmussen et al., J. Appl. Physiol., 2000; 88:386-392.) Twenty grams of intact, high quality protein has been suggested to be the maximum effective amount for stimulating muscle protein synthesis, whereas consuming greater amounts provides no additional benefit. (See Moore et al., Am. J. Clin. Nutr., 2009; 89:161-168; Koopman et al., Am. J. Physiol., 2007; 293:E833-E842; Tang et al., Appl. Physiol. Nutr. Metab., 2007; 32:1132-1138; and Levenhagen et al., Med. Sci. Sports Exerc., 2002; 34(5):828-837.) The consumption of carbohydrates and essential amino acids together has been shown to induce a greater muscle protein synthesis than essential amino acids alone. (See Miller et al., Med. Sci. Sports Exerc., 2003; 35:449-455 and Rasmussen et al., J. Appl. Physiol., 2000; 88:386-392.)
It is a further object of the invention to provide substantially clear beverage compositions in which the protein is completely dissolved. It is another object of the invention to provide recovery beverage compositions comprising protein hydrolysates, which are relatively insensitive to heat and acidity. It is yet another object of the invention to provide good tasting rehydration/recovery beverages comprising hydrolyzed proteins, which do not exhibit bitter aftertastes. These and other objects, features and advantages of the invention or of certain embodiments of the invention will be apparent to those skilled in the art from the following disclosure and description of exemplary embodiments.